A bar code is a representation of data, such as, for instance, an optical machine-readable representation of data. For example, a bar code can represent data using a number of parallel lines and/or the spacing between the lines. Such a bar code can be referred to as a one-dimensional bar code.
As an additional example, a bar code can represent data using a number of geometrical shapes and/or patterns, such as, for instance, squares, triangles, circles, dots, and/or hexagons, among other geometrical shapes and/or patterns. Such a bar code can be referred to as a two-dimensional bar code.
A bar code can be used to represent data associated with an object, among other uses. For example, a bar code representing data associated with an object can be placed on the object (e.g., on the packaging or container of the object) or embedded in the object. The bar code can then be used to recognize and/or track the object.
A bar code imager is used to read a bar code (e.g., to recognize the bar code and/or identify the data represented by the bar code). Reading a bar code can include, for example, creating and/or capturing an image of the bar code.
Covert bar codes (e.g., invisible bar codes) are bar codes that are invisible to the human eye in visible light and are activated with the use of near-infrared (NIR) or ultraviolet (UV) light. The chemicals used for printing covert bar codes determine the wavelength of the light spectrum which excites the material, rendering the bar code visible for detection and decoding.
A bar code imager used to read a covert bar code uses NIR or UV light of the necessary spectrum to activate the chemical materials of the bar code. The activated bar code thus appears to be a regular grayscale bar code, which is captured by the imager.